Your Champvallon chops are ready, enjoy with a pinch of chopped parsley.
Remarks
You can very easily replace the pork by lamb, it is even the original recipe which would be related to Mrs. De Champvallon, one of the competitors of Mrs. de Maintenon mistress then wife of King Louis XIV. Mme de Champvallon had tried with this recipe to seduce the king, who was said to be a great lover of lamb chops.
You can also replace the onions with shallots, or make a mixture of the two.
No vegetable stock on hand? Replace it with chicken stock.